Browsing by Subject "Silicon"
Now showing items 1-20 of 37
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Article
Ab-initio electronic structure calculations and properties of [SixSn1 − x]3N4 ternary nitrides
(2016)We carry out ab initio electronic structure calculations of (SixSn1 − x)3N4 using density functional theory with projector augmented-wave potentials under the generalized gradient approximation. We find that the energetically ...
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Article
Determination of critical points on silicon nanofilms: Surface and quantum confinement effects
(2008)In this work, we present a comprehensive study of the optical properties of nanocrystalline silicon films with thickness varied from 5 to 30 nm. Spectroscopic ellipsometry is employed to determine the dielectric functions ...
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Article
Effect of antimony-doping and germanium on the highly efficient thermoelectric Si-rich-Mg2(Si,Sn,Ge) materials
(2017)Two series of materials (a) Mg2Si0.55-ySn0.4Ge0.05Sby, 0 ≤ y ≤ 0.0175 and (b) Mg2Si0.5875-xSn0.4GexSb0.0125, 0 ≤ x ≤ 0.20 have been developed and studied in terms of structural features and thermoelectric properties/performance. ...
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Article
Effect of Bi-doping and Mg-excess on the thermoelectric properties of Mg2Si materials
(2014)In this work, Bi-doped magnesium silicide compounds were prepared by applying a combination of both, short-time ball milling and heating treatment. The effect of Mg excess was also studied, aiming towards further improvement ...
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Article
Electronic Structure and Thermoelectric Properties of Pseudoquaternary Mg2Si1-x-ySnxGey-Based Materials
(2014)A theoretical study is presented on complex pseudoternary Bi-doped Mg2Si1-x-ySnxGey materials, which have recently been revealed to reach high thermoelectric figures of merit (ZT) of ∼1.4. Morphological characterization ...
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Article
Ellipsometry on optically thin palladium films on silicon-based substrate: Effects of low concentration of hydrogen
(2005)Optically thin palladium films evaporated on silicon substrates are investigated following exposure to low concentrations of hydrogen gas in nitrogen using spectroscopic ellipsometry. Changes in the parameters tan Ψ and Δ ...
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Article
Femtosecond carrier dynamics in implanted and highly annealed polycrystalline silicon
(2006)We have studied the ultrafast optical response of highly implanted and highly annealed polycrystalline silicon films using 400 nm ultrashort amplified pulses with fluence ranging between 8 mJ cm-2 to 56 mJ cm -2. Transient ...
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Article
High thermoelectric figure of merit of Mg2Si 0.55Sn0.4Ge0.05 materials doped with Bi and Sb
(2013)Thermoelectric properties of new Bi- and Sb-doped Mg2Si 0.55Sn0.4Ge0.05 compounds prepared by powder methods were studied in the temperature range 300-823 K. The materials exhibited compositional inhomogeneites consisting ...
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Article
Influence of grain size on ultrafast carrier dynamics in thin nanocrystalline silicon films
(2007)The ultrafast carrier dynamics in thin nanocrystalline silicon films (10 and 20 nm thick) on quartz over a broad spectral range using optical pumping at a moderate fluence of 2.5 mJ cm2 were studied. The films were composed ...
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Article
Inhomogeneities and Effective Mass in Doped Mg2Si
(2016)Magnesium silicide (Mg2Si)-based materials are promising candidates as thermoelectric components for mid-temperature range (500–900 K) energy conversion. Many different approaches for determining the parabolicity of the ...
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Article
Inkjet printing processing conditions for bulk-heterojunction solar cells using two high-performing conjugated polymer donors
(2014)We report the processing conditions for inkjet-printed active layers of organic photovoltaic (OPV) devices comprising bulk-heterojunction blends of the low bandgap conjugated polymer poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b: ...
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Article
Large positive magnetoresistance in nonstoichiometric NiMnSb thin films on silicon
(2004)The transport properties of pulsed-laser-deposited NiMnSb films on silicon as a function of film thickness were discussed. It was found that a low-temperature upturn was observed in the resistivity for film thicknesses of ...
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Article
Low temperature growth of In 2O 3 and InN nanocrystals on Si(111) via chemical vapour deposition based on the sublimation of NH 4Cl in In
(2009)Indium oxide (In 2O 3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O 2 at 1000 °C but also at temperatures as low ...
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Article
Low temperature growth of In 2O 3 and InN nanocrystals on Si(111) via chemical vapour deposition based on the sublimation of NH 4Cl in In
(2009)Indium oxide (In 2O 3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O 2 at 1000 °C but also at temperatures as low ...
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Article
Measurement of partial widths and search for direct CP violation in D 0 meson decays to K-K+ and π -π+
(2005)We present a measurement of relative partial widths and decay rate CP asymmetries in K- K+ and π-π+ decays of D0 mesons produced in pp̄ collisions at,√s = 1.96 TeV. We use a sample of 2 × 105 D*+ →D0π+ (and charge conjugate) ...
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Conference Object
Modeling of thermal conductivity in high performing thermoelectric materials
(Institute of Physics Publishing, 2017)The enhanced TE-performance in Mg2Si-Mg2Sn based pseudo-binaries is presented, which is attributed to low thermal conductivity. Sn-Si alloying, reduces the lattice thermal conductivity due to mass fluctuation. Furthermore, ...
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Article
Observation of the narrow state X(3872) → J/ψπ+π- in p̄p collisions at √s = 1.96 TeV
(2004)The observation of a state consistent with X(3872) decaying into J/ψπ+π- was reported. The X(3872) mass was measured to be 3871.3±0.7(stat)±0.4(syst)MeV/c2 from a sample of 730±90 candidates. The observed width was consistent ...
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Article
Optically thin palladium films on silicon-based substrates and nanostructure formation: effects of hydrogen
(2000)Optically thin palladium films evaporated on different silicon-based substrates are investigated following exposure to different concentrations of hydrogen gas in air. Laser modulated reflectance off the palladium surface ...
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Article
Probing carrier dynamics in implanted and annealed polycrystalline silicon thin films using white light
(2006)Polycrystalline silicon thin film samples implanted and annealed at various temperatures have been studied using ultrafast laser pulse excitation. Nondegenerate pump-probe technique has been utilized to investigate carrier ...
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Article
Quantum confinement and interface structure of Si nanocrystals of sizes 3-5 nm embedded in a-SiO2
(2007)Spectroscopic ellipsometry and Monte Carlo simulations are employed to answer the fundamental question whether the energy gaps of Si nanocrystals with sizes in the range of 3-5 nm, which are embedded in amorphous silica, ...